This is a competitive renewal application by researchers at Ohio State University for continuing participation in the fifth iteration of the NICHD Maternal Fetal Medicine Units Network. The Network is a collaborative clinical research consortium that operates under a cooperative agreement between NICHD and participating centers that have been selected through re-competition every five years since 1986. The mission of the MFMU Network is to improve fetal and maternal outcomes through clinical research in obstetrics. Particular attention is directed to disorders that lead to preterm, low birth weight, and/or neurologically damaged infants, to the introduction of new technology into obstetrical care, and to maternal medical disorders. Problems that affect newborn infants often have their origins in pregnancy, and cause lifelong consequences such as cerebral palsy, mental retardation, hearing and vision loss, and poor school performance. Reducing the frequency and severity of the disorders addressed by MFMU Network research has the potential to improve health throughout the Irfespan of the children affected by these disorders. The Network seeks to achieve these goals through large multi-center interventional and observational clinical studies to assess the safety, efficacy and cost-effectiveness of current and new management protocols. The Network has performed randomized placebo-controlled trials of medications to prevent pre-eclampsia, preterm birth, and related morbidities such as cerebral palsy in preterm infants. The Network has also studied risk factors for preterm birth, cesarean section, asthma, and diabetes in pregnancy. Ohio State University has contributed substantially to these trials since joining the Network in 1992. This application contains a summary of contributions from Ohio State to past and current Network research, a description of the current facilities and population available at Ohio State for enrollment into current and future studies, and a concept proposal for a Network observational study that will assess the effect of stress on inflammation as a mechanism to explain racial and ethnic disparities in the rate of preterm birth.